Oil-resistant paper and packaging bags

Abstract

To provide oil resistant paper which is environmentally friendly and excellent in oil resistance and heat sealability, and a packaging bag having said oil resistant paper.SOLUTION: An oil-resistant paper according to one embodiment of the present invention is heat-sealable oil-resistant paper, which comprises a paper base material containing an oil-resistant agent and a heat-seal layer, with the paper base material laminated on one or both surfaces of the heat-seal layer, and a smoothness of the surface of the heat-seal layer measured according to JIS-P 8119 (1998) is 9 to 200 seconds.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to oil-resistant paper and packaging bags. [Background technology]

[0002] In packaging materials for prepared foods and fast food, oil-resistant paper is widely used to prevent the outer surface from becoming soiled with oil due to oil seeping from the contents.

[0003] In recent years, with changes in dietary habits, laminated paper made by laminating resin films such as polyethylene and polyethylene terephthalate has been used for oil-resistant paper bags made by heat sealing, such as bags for takeout fried foods and packaging bags for microwave ovens (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2016-22957 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, laminated paper, which has a resin film laminated onto it, has oil resistance only on the laminated surface. There is a risk that the unlaminated surface, or the interior and sides of the paper substrate, may not have oil resistance. Also, if the contents being packaged are moist, water droplets may accumulate inside the packaging and adhere to the contents, causing them to swell and degrade in quality. Furthermore, because the film remains, the laminated paper cannot be recycled as waste paper and may contribute to marine pollution as microplastics. Therefore, there is a need for an environmentally friendly oil-resistant paper with excellent oil resistance and heat-sealing properties to replace laminated paper.

[0006] This invention was made based on the circumstances described above, and aims to provide an oil-resistant paper that is environmentally friendly and has excellent oil resistance and heat-sealing properties, as well as a packaging bag having said oil-resistant paper. [Means for solving the problem]

[0007] An embodiment of the present invention is an oil-resistant paper having heat-sealing properties, comprising a paper substrate containing an oil-resistant agent and a heat-seal layer, wherein the paper substrate has a heat-seal layer laminated on one or both sides, and the smoothness of the surface of the heat-seal layer, measured in accordance with JIS-P8119(1998), is 9 seconds or more and 200 seconds or less. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide oil-resistant paper that is environmentally friendly and has excellent oil resistance and heat-sealing properties. [Modes for carrying out the invention]

[0009] [Description of Embodiments of the Invention] An oil-resistant paper according to one embodiment of the present invention is an oil-resistant paper having heat-sealing properties, comprising a paper substrate containing an oil-resistant agent and a heat-seal layer, wherein the paper substrate has a heat-seal layer laminated on one or both sides, and the smoothness of the surface of the heat-seal layer, measured in accordance with JIS-P8119(1998), is 9 seconds or more and 200 seconds or less.

[0010] This oil-resistant paper exhibits excellent oil resistance even within the paper substrate, due to the inclusion of an oil-resistant agent in the paper substrate. Furthermore, the smoothness of the surface of the heat-seal layer, being between 9 and 200 seconds, improves the blocking suppression effect between heat-seal layers. Therefore, this oil-resistant paper provides excellent oil resistance and heat-sealability. In addition, since this oil-resistant paper does not use a resin film, it is environmentally friendly.

[0011] Preferably, the oil-resistant paper has a smoothness of 8 seconds or more and 30 seconds or less on the surface of the paper substrate on which the heat-seal layer is laminated, as measured in accordance with JIS-P8119 (1998). A smoothness of 8 seconds or more and 30 seconds or less further improves the blocking suppression effect between the heat-seal layers.

[0012] It is preferable that the heat seal layer contains an olefin resin as its main component. By containing an olefin resin as its main component, the heat seal strength can be achieved not only at room temperature but also at low temperatures.

[0013] The main component of the above-mentioned oil-resistant agent is preferably a fluororesin, an acrylic resin, a synthetic rubber latex, or a combination thereof. The oil-resistant paper possesses good oil resistance because the main component of the above-mentioned oil-resistant agent is a fluororesin, an acrylic resin, or a synthetic rubber latex.

[0014] The amount of oil resistant agent added is preferably 4.0 kg / t to 10.0 kg / t relative to the pulp fibers of the paper substrate. When the amount of oil resistant agent added relative to the pulp fibers of the paper substrate is within this range, excellent oil resistance and adhesion between the paper substrate and the heat seal layer are achieved. "kg / t" represents the amount added (kg) per ton of pulp fibers of the paper substrate.

[0015] The moisture permeability of this oil-resistant paper, in accordance with JIS-Z0208 (1976), is 600 g / m². 2 ·1500g / m for 24 hours or more 2 It is preferable that the moisture permeability of the oil-resistant paper is 24 hours or less. When the moisture permeability of the oil-resistant paper is within the above range, the moisture in the packaged contents is less likely to turn into water droplets, and the humidity is maintained at an appropriate level, thus preserving the quality of the contents well.

[0016] Another embodiment of the present invention provides a packaging bag having the oil-resistant paper. Because this packaging bag has the oil-resistant paper, it has excellent oil resistance and heat-sealability.

[0017] [Details of the Embodiments of the Invention] Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be based on representative embodiments and specific examples, but the present invention is not limited to such embodiments. Hereinafter, an oil-resistant paper according to an embodiment of the present invention will be described in detail. The blending amount (dry internal addition amount) of each material blended in the paper base material described below refers to the mass ratio to the dry mass of the pulp of the paper base material, unless otherwise specified. In addition, the content rate of each material blended in the heat-sealing layer forming composition refers to the dry mass ratio of each material to the total mass of the heat-sealing layer, unless otherwise specified.

[0018] <Oil-resistant paper> The oil-resistant paper includes a paper base material and a heat-sealing layer on at least one surface of the paper base material. The heat-sealing layer may be either a single-layer or a multi-layer structure.

[0019] [Paper base material] The paper base material is obtained by papermaking a slurry containing raw pulp. The paper base material may be either a single layer or a multi-layer. (Raw pulp) The paper base material preferably consists mainly of raw pulp. As the raw pulp constituting the paper base material, for example, virgin pulp, waste paper pulp, a combination of these pulps, etc. can be used.

[0020] Examples of virgin pulp include chemical pulps such as hardwood bleached kraft pulp (LBKP), softwood bleached kraft pulp (NBKP), hardwood unbleached kraft pulp (LUKP), softwood unbleached kraft pulp (NUKP), hardwood semi-bleached kraft pulp (LSBKP), softwood semi-bleached kraft pulp (NSBKP), hardwood sulfite pulp, softwood sulfite pulp, etc.; mechanical pulps (MP) such as stone ground pulp (SGP), pressure stone ground pulp (TGP), chemiground pulp (CGP), groundwood pulp (GP), thermomechanical pulp (TMP), etc., which are produced chemically or mechanically. These can be used alone or in combination of a plurality of them.

[0021] As recycled paper pulp, for example, disintegrated recycled paper pulp, disintegrated and deinked recycled paper pulp (DIP), disintegrated, deinked and bleached recycled paper pulp, etc., manufactured from brown recycled paper, kraft envelope recycled paper, magazine recycled paper, newspaper recycled paper, flyer recycled paper, office recycled paper, corrugated cardboard recycled paper, white recycled paper recycled paper, Kent recycled paper recycled paper, imitation recycled paper recycled paper, land destiny recycled paper recycled paper, etc., can be used individually or in combination of multiple types.

[0022] (Oil resistant agent) Oil-resistant agents can be added one or more of the following compounds in combination: fluororesins, starch, cellulose derivatives, gelatin, casein, soy protein, polyvinyl alcohol, polyisoprene, polymers or copolymers of chloroprene, polydiene, polyalkenes, polymers or copolymers of vinyl monomers, synthetic rubber latex, polyurethane resins, polyester resins, polyamide resins, olefin-maleic anhydride resins, silicone resins, acrylic resins, melamine resins, plant waxes, animal waxes, mineral waxes, petroleum waxes, synthetic hydrocarbon waxes, 12-hydroxystearic acid amide, stearic acid amide, phthalic acid imide anhydride, higher fatty acid amides or esters or ketones or ethers of chlorinated hydrocarbons. Among the above oil-resistant agents, from the viewpoint of oil resistance, it is preferable to add oil-resistant agents mainly composed of acrylic resins, synthetic rubber latex, and fluororesins, and fluororesins are particularly preferred. This oil-resistant paper achieves superior oil resistance even with a lower additive amount, both internally and externally, by adding an oil-resistant agent whose main component is a fluororesin to the paper substrate. It is presumed that the high surface tension of the fluororesin allows the oil-resistant agent to disperse easily within the paper substrate, enabling it to exhibit oil resistance even with a low additive amount.

[0023] Examples of the fluororesins mentioned above include anionic fluororesins and cationic fluororesins. Commercially available anionic fluororesins include Asahi Guard® AG-E080 and AG-E090 from Asahi Glass Co., Ltd., Unidyne® TG-8111 and TG8731 from Daikin Industries, Ltd., and Solvay® PT5060 and PT5045 from Solvay. Commercially available cationic fluororesins include Asahi Guard® AG-E060 and AG-E070 from Asahi Glass Co., Ltd., and Capstone® P620 and P623 from DuPont. Among these, anionic fluororesins are preferred from the viewpoint of obtaining oil resistance with a low additive amount.

[0024] The lower limit of the amount of oil-resistant agent added is preferably 4.0 kg / t relative to the pulp fibers of the paper substrate. The upper limit of the amount of oil-resistant agent added is preferably 10.0 kg / t, and more preferably 8.0 kg / t, relative to the pulp fibers of the paper substrate. When the amount of oil-resistant agent added relative to the pulp fibers of the paper substrate is within the above range, excellent oil resistance and adhesion between the paper substrate and the heat seal layer are achieved.

[0025] (Other additives) Other additives may be added to the paper substrate as needed. Examples of additives include fillers, pigments, sizing agents, binders, oil resistant agents, fluorescent whitening agents, aluminum sulfate, yield enhancers, water drainage enhancers, dry strength enhancers, wet strength enhancers, coloring dyes, coloring pigments, and water-resistant agents, which can be used individually or in combination.

[0026] (Papermaking) The papermaking method for paper substrates can be carried out using a known paper machine with a raw material slurry containing the above-mentioned raw pulp and additives. A calendering step can also be included if necessary.

[0027] [Heat seal layer] The heat seal layer is formed by coating one or both sides of a paper substrate with a heat seal layer forming composition.

[0028] The heat-seal layer described above preferably contains an olefin resin as its main component. Examples of olefin resins include polyethylene resins and polypropylene resins. Examples of polyethylene resins include low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), ethylene acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate copolymer (EMA), ethylene-vinyl acetate copolymer (EVA), carboxylic acid-modified polyethylene, ionomers, and their derivatives, as well as mixtures thereof. Examples of polypropylene resins include polypropylene (PP) homopolymer, random polypropylene (random PP), block polypropylene (block PP), chlorinated polypropylene, carboxylic acid-modified polypropylene, and their derivatives, as well as mixtures thereof. Among these, ethylene acrylic acid copolymer is more preferred from the viewpoint of heat-sealability in the low-temperature range of around 100 to 130°C.

[0029] The lower limit of the olefin resin content relative to the total solid content of the heat seal layer is 50.0% by mass, preferably 90.0% by mass. If the olefin resin content is less than 50.0% by mass, sufficient heat sealability may not be obtained. On the other hand, the upper limit of the olefin resin content is 100.0% by mass, preferably 95.0% by mass.

[0030] (Other additives) The heat seal layer of the present invention may contain other additives besides those mentioned above. Other additives may include, for example, water-soluble polymers, adhesives, inorganic pigments, organic pigments, sizing agents, viscosity modifiers, coloring dyes, coloring pigments, water-resistant agents, lubricants, etc., which can be used individually or in combination.

[0031] [Physical properties of oil-resistant paper] (Smoothness) The lower limit of the Beck smoothness of the surface of the heat seal layer, measured in accordance with JIS-P8119 (1998), is 9 seconds, with 15 seconds being more preferable. The upper limit of the smoothness is 200 seconds, with 150 seconds being more preferable. If the smoothness is below the lower limit, the surface of the oil-resistant paper becomes rough (the contact area becomes smaller), which may reduce the heat seal strength. If the smoothness exceeds the upper limit, the blocking suppression effect of the heat seal layer may decrease. By having the smoothness of the surface of the heat seal layer between 9 seconds and 200 seconds, the blocking suppression effect between the heat seal layers can be improved, and the adhesion of contents can be prevented.

[0032] Furthermore, the lower limit of the smoothness of the surface of the paper substrate on which the heat seal layer is laminated is preferably 5 seconds, and more preferably 8 seconds. The upper limit of the smoothness is preferably 180 seconds, and more preferably 30 seconds. If the smoothness is below the lower limit, the surface of the oil-resistant paper becomes rough (has many voids), causing the heat seal layer coating liquid to penetrate too deeply into the paper substrate, which may reduce the heat seal strength. If the smoothness exceeds the upper limit, the blocking suppression effect between the heat seal layers may decrease.

[0033] (Oil resistance) The lower limit of the kit value, which is an indicator of the oil resistance of the oil-resistant paper, is preferably 5 or higher, and more preferably 6 or higher. If the kit value is less than 5, the paper may not be able to function as oil-resistant paper. There is no particular upper limit to the kit value of the oil-resistant paper. Here, "kit value" refers to the oil resistance of the surface and cross-section measured under conditions of 23°C and 50% humidity (JAPAN TAPPI No. 41 Paper and cardboard - Oil repellency test method - Kit value by kit method), and the higher the value, the higher the oil resistance.

[0034] (moisture permeability) The moisture permeability of the oil-resistant paper shall be measured according to JIS-Z0208

[1976] Moisture Permeability Test Method for Moisture-Proof Packaging Materials [Cup Method], based on condition B. When the oil-resistant paper is used in bag making, the lower limit of the above moisture permeability shall be 600 g / m².2 24 hours is preferable, and 900 g / m² 2 24h is preferable. Also, the upper limit for the above moisture permeability is 1500g / m². 2 24 hours is preferable, and 1200 g / m² 2 24h is preferable. Because the above moisture permeability is within the above range, the packaged contents have good oil resistance, and moisture is less likely to turn into water droplets, thus maintaining a moderate level of humidity and preserving the quality of the contents.

[0035] This oil-resistant paper provides excellent oil resistance and heat-sealing properties. Furthermore, because it has a disintegrable heat-sealable layer, it is recyclable and does not use a resin film, thus contributing to environmental protection.

[0036] [Method for manufacturing oil-resistant paper] The method for manufacturing the oil-resistant paper is not particularly limited, but for example, it includes the steps of: making paper from a pulp slurry that will be used as a raw material for a paper substrate; producing a heat-seal layer forming composition; and coating at least one surface of the paper substrate with the heat-seal layer forming composition.

[0037] In the papermaking process, a raw material slurry containing the aforementioned raw pulp, oil resistant agent, and other additives is processed using a known papermaking machine.

[0038] Next, it is preferable to include a step of drying one side of the paper substrate produced in the above papermaking process using a Yankee dryer to form a glossy surface. In this step, the surface in contact with the Yankee dryer is formed as the glossy surface. More specifically, a so-called blanket is used to press wet paper against the Yankee dryer, and the mirror surface of the Yankee dryer's cylinder is transferred to the wet paper, thereby obtaining a glossy surface for one-sided glossy kraft paper. In the drying process with the Yankee dryer, the surface temperature of the dryer is in the range of 100°C to 150°C, and the paper is pressed against the mirror surface of the Yankee dryer. The non-contact surface with the Yankee dryer is formed as a non-glossy surface. On the non-glossy side, the smoothness is adjusted by the material of the blanket and the pressure applied by the touch roll that presses the blanket against the Yankee dryer. Among the above adjustment methods, the method using the pressure applied by the touch roll is preferred. As a result, it is possible to widen the difference in smoothness between the glossy and non-glossy surfaces while maintaining the density of the paper substrate. The paper substrate having a glossy surface and a matte surface, when a heat-seal layer is laminated on the matte surface, exhibits a blocking suppression effect, and the matte surface can exhibit excellent printability. Here, "glossy surface" refers to the surface that has gloss, and "matte surface" refers to the surface that does not have gloss.

[0039] As described above, the Beck smoothness of the surface of the paper substrate on which the heat seal layer is laminated is preferably 8 seconds to 30 seconds, but if the oil-resistant paper has a heat seal layer on one side, the Beck smoothness of the non-glossy side of the paper substrate is adjusted to this range.

[0040] In the process of producing a heat seal layer-forming composition, a heat seal layer-forming composition containing an olefin resin as the main component is produced.

[0041] A known coating method can be used for coating the heat seal layer-forming composition, and known coating machines such as a 2-roll size press coater, gate roll coater, blade metering coater, rod metering coater, blade coater, air knife coater, roll coater, brush coater, kiss coater, squeeze coater, curtain coater, die coater, bar coater, and gravure coater can be used.

[0042] The lower limit for the coating amount (in terms of solid content) on one side of the heat seal layer forming composition is 2.5 g / m². 2 This is preferable. If the above coating amount does not meet the above lower limit, the heat seal layer may not have sufficient oil resistance and heat sealability. On the other hand, the upper limit of this coating amount is 3.5 g / m 2 This is preferable. If the above coating amount exceeds the above upper limit, the blocking suppression effect may decrease. Also, if the coating layer becomes too thick, coating residue may be more likely to be generated during the folding process when processing into packaging bags.

[0043] For drying the coated heat-seal layer-forming composition, known drying equipment can be used, such as infrared drying equipment, hot air drying equipment, contact dryer drying equipment, etc.

[0044] The oil-resistant paper obtained in this way can be finished using various known finishing devices, such as supercalenders, gloss calenders, soft calenders, and matte calenders, and can be given a product finish as appropriate.

[0045] <Packaging bag> Another embodiment of the present invention provides a packaging bag having the oil-resistant paper. Because the packaging bag has the oil-resistant paper, it has excellent oil resistance and heat-sealing properties. Furthermore, because it has high moisture permeability, moisture from the contents is less likely to turn into water droplets, and the quality of the contents can be well maintained by keeping the humidity at an appropriate level.

[0046] <Other Embodiments> The present invention is not limited to the above embodiments, and can be implemented in various modified and improved forms in addition to the above aspects.

[0047] Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited to the following examples.

[0048] [Examples 1 to 9 and Comparative Examples 1 to 2] (Manufacture of paper base material) First, 100% by mass of hardwood kraft pulp [LBKP] was prepared to obtain a pulp slurry. To this pulp slurry, an oil-resistant agent (fluororesin: "Unidyne TG8811" manufactured by Daikin Industries, Ltd., synthetic rubber latex: commercially available product, acrylic resin: commercially available product) was added in the amounts shown in Table 1. In addition, as other additives, sulfuric acid band, yield improver, and sizing agent were added internally. The obtained pulp slurry was formed into a paper base material by papermaking using an on-top type fourdrinier paper machine. The basis weight of the paper base material was 50.0 g / m 2 It was.

[0049] (Lamination of heat seal layer) Next, a heat seal layer was formed on one side of the paper base material to obtain an oil-resistant paper with a basis weight of 53.0 g / m 2 The composition of the composition for forming the heat seal layer was as shown in Table 1. In addition, the following products were used for the olefin resin and coating amount used in the composition for forming the heat seal layer. In Table 1 below, "-" indicates that the corresponding component was not used.

[0050] [Comparative Example 3] A single-layer laminated paper containing a polypropylene film was produced. The base paper was composed of commercially available kraft paper (basis weight 50.0 g / m 2 ). The polypropylene film was extruded and laminated on a base paper with a thickness of 20 μm on only one side by using a commercially available polypropylene resin with a pelletizer.

[0051] Various evaluations were performed on the oil-resistant papers obtained as described above.

[0052] (Smoothness) The Beck smoothness of the surface of the heat seal layer and the surface of the paper substrate to which this heat seal layer is laminated was measured in accordance with JIS-P8119 (1998).

[0053] (Oil resistance) The kit values ​​of the surface and cross-section of oil-resistant paper were measured in accordance with JAPAN TAPPI No. 41 Paper and cardboard - Oil repellency test method - Kit method. A kit value of 5 or higher indicates good oil resistance.

[0054] (moisture permeability) The moisture permeability of the oil-resistant paper in the examples and comparative examples was measured under condition B in accordance with JIS-Z0208

[1976] Moisture permeability test method for moisture-proof packaging materials [cup method].

[0055] (Heat seal strength) Using a thermal gradient tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.), the peel strength of the heat-sealed portion was measured using a load cell type tensile tester after processing under atmospheric pressure of 2 atm, sealer pressure of 2 kg / cm, sealer time of 1 second, and sealer temperature of 140°C. The evaluation criteria were as follows (three levels). A rating of ○ or △ indicates good heat seal strength. ○: The peel strength is 3.0 N / 25 mm or higher. △: Peel strength is 2.0 N / 25 mm or more and less than 3.0 N / 25 mm. ×: The peel strength is less than 2.0 N / 25 mm.

[0056] (Blocking suppression) For each example and comparative example, the heat-sealed surfaces of two sheets of oil-resistant paper were brought into close contact, and a 1 kg pressure roller was applied with one back-and-forth pressure. Next, after being stored for one day under conditions of 40°C, the results of peeling them off by hand were evaluated according to the following three criteria. A rating of ○ or △ indicates good blocking suppression. ○: No blocking occurs, and peels off smoothly. △: There is some slight blocking, but the peelability is within an acceptable range. ×: Blocking is occurring, making it difficult to peel off.

[0057] Table 1 shows the evaluation results for each example and comparative example.

[0058] [Table 1]

[0059] As shown in Table 1, Examples 1 to 9, which included a paper substrate containing an oil-resistant agent and had a surface smoothness of 9 seconds to 200 seconds for the heat-seal layer, exhibited good oil resistance, heat-seal strength, and blocking suppression. In particular, the examples in which the surface smoothness of the paper substrate on which the heat-seal layer is laminated was 8 seconds to 30 seconds, and the coating amount of the heat-seal layer forming composition on one side was 2.5 g / m², showed good oil resistance, heat-seal strength, and blocking suppression. 2 More than 3.5g / m 2 Examples 1 to 3 below demonstrated excellent heat seal strength and blocking suppression. On the other hand, the oil-resistant papers of Comparative Examples 1 and 2, in which the surface smoothness of the heat-seal layer was less than 9 seconds or more than 200 seconds, were inferior in either heat-seal strength or blocking suppression. Comparative Example 3 is made of polypropylene (PP) laminated paper, which is undesirable from an environmental pollution standpoint. Furthermore, due to its low moisture permeability, it is considered that using it as a packaging bag may lead to a decrease in the freshness of the contents. As described above, the oil-resistant paper has been shown to have excellent oil resistance and heat-sealing properties. Furthermore, because this oil-resistant paper has a heat-sealable layer that can be disassembled, it can be recycled, and since it does not use a resin film, it contributes to environmental protection. [Industrial applicability]

[0060] The oil-resistant paper of the present invention is environmentally friendly, has excellent oil resistance and heat-sealing properties, and is suitable for packaging food and other products.

Claims

1. Oil-resistant paper with heat-sealing properties, Paper substrate and Heat seal layer and Equipped with, The above paper substrate has a heat-seal layer laminated on one or both sides, The above heat-seal layer does not contain inorganic pigments. The smoothness of the surface of the heat seal layer, as measured in accordance with JIS-P8119 (1998), is between 9 seconds and 200 seconds. The surface has an oil resistance rating of 5 or 6. Oil-resistant paper with a moisture permeability of 600 g / m²·24h or more and 1500 g / m²·24h or less, in accordance with JIS-Z0208 (1976).

2. An oil-resistant paper having heat-sealing properties, Paper substrate and Heat seal layer and Equipped with, The above paper substrate has a heat-seal layer laminated on one or both sides, The above heat-seal layer does not contain inorganic pigments. The smoothness of the surface of the heat seal layer, as measured in accordance with JIS-P8119 (1998), is between 9 seconds and 200 seconds. The surface has an oil resistance rating of 5 or 6. Oil-resistant paper having an ethylene acrylic acid copolymer content of more than 90.0% by mass in the heat-seal layer described above.

3. The oil-resistant paper according to claim 1 or claim 2, wherein the smoothness of the surface of the paper substrate on which the heat-seal layer is laminated is measured in accordance with JIS-P8119 (1998) and is 8 seconds or more and 30 seconds or less.

4. A packaging bag having oil-resistant paper according to any one of claims 1 to 3.

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